Why do patients engage in medical tourism?

Medical tourism is commonly perceived and popularly depicted as an economic issue, both at the system and individual levels. The decision to engage in medical tourism, however, is more complex, driven by patients¿ unmet need, the nature of services sought and the manner by which treatment is accessed. In order to beneficially employ the opportunities medical tourism offers, and address and contain possible threats and harms, an informed decision is crucial. This paper aims to enhance the current knowledge on medical tourism by isolating the focal content of the decisions that patients make. Based on the existing literature, it proposes a sequential decision-making process in opting for or against medical care abroad, and engaging in medical tourism, including considerations of the required treatments, location of treatment, and quality and safety issues attendant to seeking care. Accordingly, it comments on the imperative of access to health information and the current regulatory environment which impact on this increasingly popular and complex form of accessing and providing medical care

Wavelength-dependent spatial variation in the reflectance of 'homogeneous' ground calibration targets (Paper presented at XIX ISPRS Congress, 16-22 July, 2000, Amsterdam, The Netherlands)

Remotely sensed data are most useful if calibrated to spectral reflectance of known features. One simple method of calibration is regression of remote data on the reflectance of several ground targets as measured in the field, the so called empirical line method (ELM). The ideal situation would be one where a range of ground targets representing all the features of interest in the remote image were available for ground measurements (Lawless et al., 1998). The identification of suitable ground targets is constrained by several limitations, such as their size (to minimise edge effects), their absolute reflectance (to represent spectral characteristics of the image) and their effective spatial variability (to extract reflectance characteristics representative of the target). The size of a ground target is dependent on the spatial resolution of the image that must be calibrated (Justice & Townshend, 1981) and the number of observations needed to represent features in the image has been suggested to depend upon the spatial resolution of the remotely sensed image (Justice & Townshend, 1981) and on the spatial variability of the ground target (Harlan et al., 1979; Curran & Williamson, 1986). Although ground targets used for calibration should be spectrally “bland” and spatially uniform by definition (Clark et al., 1999), it is sometimes very difficult to find such places available for calibrating remotely sensed images. When surfaces that apparently satisfy these conditions are available in suitable size, their sampling needs to be designed to optimise representation of the whole surface and available resources (e.g., effort and time). Surfaces that look spatially uniform by eye may actually contain spatial variation, and this spatial variation may depends on wavelength (Atkinson & Emery, 1999). Such variability can be detected using geostatistics, which is concerned with issues such as spatial correlation and analyses of spatial data. Geostatistical tools have been used in a variety of studies and the variogram has been applied in remote sensing and ecology to design optimal sampling strategies for variables sampled in space (Atkinson, 1991; Rossi et al., 1992) and time (Salvatori et al., 1999). This study investigates the spatial variability of potentially suitable ground calibration targets (GCT) using a geostatistical approach, which gives results that can be used to design optimal sampling strategies for such surfaces. The targets were selected from an area where an Itres Instruments Compact Airborne Spectral Imager (casi) with ground resolution of about 1.5 metres was flown at the same time as ground data were acquired

Environmental Policy, the Porter Hypothesis and the Composition of Capital: Effects of Learning and Technological Progress

In this paper the e.ect of environmental policy on the composition of capital is investigated.By allowing for non-linearities it generalizes Xepapadeas and De Zeeuw (Journal of Environmental Economics and Management, 1999) and determines scenarios in which their results do not carry over.In particular, we show that the way acquisition cost of investment decreases with the age of the capital stock is of crucial importance.Also it is obtained that environmental policy has opposite e.ects on the average age of the capital stock in the case of either deterioration or depreciation.We also focus more explicitly on learning and technological progress.Among others we obtain that in the presence of learning, implementing a stricter environmental policy with the aim to reach a certain target of emissions reduction has a stronger negative e.ect on industry pro.ts, which implies quite the opposite as to what is described by the Porter hypothesis.environmental policy;capital;learning;technological change

Dynamic Investment Behavior Taking into Account Ageing of the Capital Good

In standard capital accumulation models all capital goods are equally productive and produce goods of the same quality.However, due to ageing, in reality it holds most of the time that newer capital goods are more productive. Implications of this feature for the firm's investment policies are investigated in an optimal control problem with distributed parameters.It turns out that investing in capital goods of di¤erent age is done such that the net present value of marginal investment equals zero.Comparing the returns of investment in capital goods of different age, the higher productivity of younger capital goods has to be weighed against the lower costs of depreciation, discounting and acquisition of older capital goods.In the steady state it holds that, in the most reasonable scenario, the firm should invest at the highest rate in new capital goods, and dis-investment can only be optimal when costs of acquisition are large and machines are old.investment;capital goods;ageing

Simulation of Beam-Beam Effects and Tevatron Experience

Effects of electromagnetic interactions of colliding bunches in the Tevatron had a variety of manifestations in beam dynamics presenting vast opportunities for development of simulation models and tools. In this paper the computer code for simulation of weak-strong beam-beam effects in hadron colliders is described. We report the collider operational experience relevant to beam-beam interactions, explain major effects limiting the collider performance and compare results of observations and measurements with simulations.Comment: 23 pages, 17 figure

The Non-Trivial Effective Potential of the `Trivial' lambda Phi^4 Theory: A Lattice Test

The strong evidence for the `triviality' of (lambda Phi^4)_4 theory is not incompatible with spontaneous symmetry breaking. Indeed, for a `trivial' theory the effective potential should be given exactly by the classical potential plus the free-field zero-point energy of the shifted field; i.e., by the one-loop effective potential. When this is renormalized in a simple, but nonperturbative way, one finds, self-consistently, that the shifted field does become non-interacting in the continuum limit. For a classically scale-invariant (CSI) lambda Phi^4 theory one finds m_h^2 = 8 pi^2 v^2, predicting a 2.2 TeV Higgs boson. Here we extend our earlier work in three ways: (i) we discuss the analogy with the hard-sphere Bose gas; (ii) we extend the analysis from the CSI case to the general case; and (iii) we propose a test of the predicted shape of the effective potential that could be tested in a lattice simulation.Comment: 22 pages, LaTeX, DE-FG05-92ER40717-

Photoluminescence rings in Corbino disk at quantizing magnetic fields

Spatially resolved photoluminescence of modulation doped AlGaAs/GaAs heterojunction was investigated in a sample of Corbino disk geometry subject to strong perpendicular magnetic fields. Significant spatial modulation of the photoluminescence was observed in form of one or more concentric rings which travelled across the sample when the magnetic field strength was varied. A topology of the observed structure excludes the possibility of being a trace of an external current. The effect is attributed to formation of compressible and incompressible stripes in a 2DEG density gradient across the sample.Comment: 5 two-column pages, 4 figures (one of them in color

Advanced Magnetostrictive Materials for Sonar Applications

Piezoelectric or magnetostrictive materials can be utilised as active materials for electroacoustic underwater transducers. Piezoceramic materials gained edge over the conventional magnetostrictive materials during 1940s due to their unique electro-acoustic properties. At present, inspite of passive sonars there is a need of low-frequency high-power active sonars for the Navy. This led toresearch for new activematerials with competing characteristics to that of the existing piezo transducers. The discovery of a giant magnetostrictive material, commercially known as Terfenol-D, led to a breakthrough in the development of a new generation of sonar transducers. Now, the materials (including composites) as well as sensors are commercially available. A new generation of transducers have emerged in ocean-related areas like acoustic tomography, longrange underwater communication, geophysical exploration, oil well exploration, etc.Indian Institute of Technology Madras, Chennai, has also developed the basic material technology a few years back. At present, in India, National Institute of Ocean Technology, Chennai, is developing underwater transducers utilising giant magnetostrictive materials as well as piezoelectric materials for marine applications like sub-bottom profiling (seafloor mapping) and long-range underwater communications. A prototype of a portable, low-frequency medium power transmitter operating over a wide-frequency range has been developed. The main advantage of this transducer is its simplicity in design. In this paper, (he recent developments in material processes, importance of device-oriented material characterisation, and transducer design aspects have been emphasised. Some results on the underwater performance of a wide-band transducer have also been presented. These materials also have ultrasonic applications, capable of revolutionising the processing industry

The effects of thermal radiation and viscous dissipation on MHD heat and mass diffusion flow past an oscillating vertical plate embedded in a porous medium with variable surface conditions

This investigation is undertaken to study the hydromagnetic flow of a viscous incompressible fluid past an oscillating vertical plate embedded in a porous medium with radiation, viscous dissipation and variable heat and mass diffusion. Governing equations are solved by unconditionally stable explicit finite difference method of DuFort - Frankel’s type for concentration, temperature, vertical velocity field and skin - friction and they are presented graphically for different values of physical parameters involved. It is observed that plate oscillation, variable mass diffusion, radiation, viscous dissipation and porous medium affect the flow pattern significantly